Boat trimming means



June 27, 1967 M. COMINS 3,327,671

BOAT TRIMMING MEANS Filed Oct. 14, 1965 2 Sheets-Sheet 1 INVENTOR C MAX COMINS I I ATTORNEYS June 27, 1967 M. COMINS 3,327,671

BOAT TR IMMING MEANS Filed Oct. 14, 1965 2 Sheets-Sheet 2 Hf lll l LI 7 FIG? 54 4o I30 0; INVENTOR i i! HI y. .MAXCOMS FIGB V I70 ATTO RN EYS United States Patent 3,327,671 BOAT TRIMMING MEANS Max Comins, 14680 Abington, Detroit, Mich. 48227 Filed Oct. 14, 1965, Ser. No. 495,942 13 Claims. (Cl. 114-665) The present invention relates to marine craft such as small motor powered boats and the like and more particularly to an improved means for selective trimming of such craft.

Small marine craft has the tendency to assume an attitude with the forward end inclined upwardly from the horizontal during movement through the water. The degree of such inclination depends not only on the design of the boat but the loading and the boat speed as well so that it is almost impossible to design small boats that will not include upwardly at some speed and under some load conditions. When the inclination is severe steerin and vision are made difficult and maximum engine efficiency and boat speed cannot be achieved.

To overcome this problem means have been heretofore provided which increase the effective length of the craft and thereby maintain the craft horizontal at higher speeds and with greater load conditions. These means have generally taken the form of flaps or tabs provided on the underside of the transom of the boat increasing the effective surface of the chaft. In one form the tabs are carried in a fixed position and in another the tabs or flaps are hingedly or pivotally mounted in position to be moved in and out of the water. This latter form permits the effective length of the craft to be adjusted by varying the angle at which the tabs extend into the water and permits the flap or tab to be completely withdrawn from the water when this is desired.

Of these two forms the latter is the most desirable in that it permits adjustment to meet the effect of changing engine speeds and load condiions while with fixed tabs this is not possible and the tabs will either produce too much drag at low speeds and under light load conditions or they will not plane the craft at high boat speeds and under heavy load conditions. Such fixed tabs must be designed to plane the boat at higher speeds for if they are designed to plane at moderate speeds the danger of over trim is produced at higher speeds. It is also desirable to permit withdrawal of the tab from the water and this is of course not possible with fixed tabs. Withdrawal might be desirable in shallow water to prevent the tab from being damaged and is certainly desirable when the craft is being operated in a following sea or where the wind is in the same direction the boat is traveling. If the tab cannot be removed from the water waves produced during a following sea will strike against the undersurface of the tab to cause the craft to pitch and to interfere with steermg.

The present invention provides a trim means which is an improvement over either of the two general types of such means heretofore used. As will become more apparent as the description proceeds tabs are provided which extend angularly from either the underside or the transom of a marine craft. Unlike the fixed tab construction heretofore known however, means are provided for adjusting the extended position of the tabs and if desired the tabs can be completely retracted from the water. Unlike the pivotally or hingedly connected tabs heretofore provided adjustment is accomplished by varying the amount of the tab extending into the water without varying the angle at which the tab extends. This has been found to produce a more accurate and more efiicient adjustment in that it permits the effective length of the craft to be varied in smaller increments than possible with those systems-in which the effective length is varied by pivotally or hingedly mounted tabs. Further, the trim means of the present invention permits the trimming tabs to be retreated to a protected position within the craft so that the tabs cannot be damaged by accident or collision and to provide safety in a following sea. The trim means of the present invention also has the advantage over heretofore known pivotally mounted tabs in that there is no linkage or pivoted connectors exposed to the water. Thus malfunction due to rusting is avoided.

It is an object then of the present invention to provide an improved trim attachment for small marine craft and the like by providing a trimming tab and means for variably extending the tab from the craft.

It is another object of the present invention to increase the maximum speed and to facilitate steering at high speeds of marine craft and the like by providing a trimming means for such craft at a fixed angle and means for selectively extending and retracting the tab to adjustably vary the surface of the tab disposed within the water.

It is still another object of the present invention to increase the efficiency and the life of trim tabs for marine craft and the like by providing means selectively operable go retract the trim tab to a protected position within the oat.

Still further objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains upon reference to the following description. The description makes reference to the accompanying drawings in which like reference characters refer to like parts throughout the several views and in which,

FIG. 1 is a fragmentary perspective view of the stern of a power craft illustrating the trim tabs of the present invention in an extended position,

FIG. 2 is a cross-sectional view through one of the trim tabs shown in FIG. 1,

FIG. 3 is a cross-sectional view taken substantially on line 3-3 of FIG. 2,

FIG. 4 is a cross-sectional from line 4-4 of FIG. 2,

FIG. 5 is a view similar to FIG. modified structure of the trim tabs.

FIG. 6 is a view similar to FIG. 2 but illustrating another preferred trimming means of the present invention,

FIG. 7 is a cross-sectional view taken substantially on line 77 of FIG. 6, and

FIG. 8 is a top plan view of another preferred modification of the trim tabs of the present invention.

view as seen substantially 4 but illustrating a Description Referring to FIG. 1 the present invention is intended for use with a power boat 10 which is illustrated as having a transom 12 and a bottom 14. In one preferred form of the invention as illustrated in FIGS. 1-4 trim members or tabs 16 are mounted to extend from the transom 12 with one of the tabs 16 on each side of the longitudinal center line of the boat 10.

As can best be seen in FIGS. 2-4 each of the tabs 16 is slidably mounted in a compartment 20 formed by upper and lower Walls 22 and 24 respectively, by side walls 26 and by an inner end wall 28. The transom 12 is provided with openings 30 in registry with the compartments 20 to permit the tabs 16 to be slidably moved past the transom 12.

The compartment 20 is of sufiicient dimensions to permit the tabs r16 to be retracted to a position completely within the compartment 20.

The upper walls 22 and the lower walls 24 are parallel and extendat an angle inclined upwardly with respect to bottom 14 from the transom 12 toward the front of the boat 10 preferably at an angle of approximately l0 degrees.

The tabs 16 are generally rectangular and fiat and as can best be seen in FIG. 4 in one preferred construction the tabs 16 are preferably molded or formed of plastic or similar material to produce side runners 32. The runners 32 are received in guide channels 34 formed in the compartment 24) by providing an upstanding guide member 36 spaced from each of the side walls 26.

FIG. discloses another preferred construction of the trim tabs 16 in which a metal such as stainless steel or the like is used and therefore in which the runners 32 are formed by bending the side edges of the tabs 16.

The runners 32 and the channels 34 formed by the guides 36 provide a means for guiding the tabs 16 in sliding movement into and out of the compartment 20 so as to minimize friction and to prevent the tabs 16 from 'becoming wedged in the compartment 20.

Each tab 16 is adapted to be individually moved into and out of the respective compartment 20 by a suitable mechansm which as can best be seen in FIGS. 2-3 comprises a shaft 38 one end of which is fixed to the rear undersurfacc of the tab 16 by a clamp 40. The shaft 38 is slidable through an opening 42 provided in the end wall 28. A seal 44 is mounted by a retainer 46 to the end wall 28 to prevent water from entering the boat from the compartment along the shaft 38.

As can best be seen in FIG. 3 an electric motor 48 is mounted to a support 50 and has a pinion 52 which meshes with a screw shaft 54. The shaft 38 is internally threaded (not shown) to receive the screw shaft 54 so that rotation of the screw shaft 54 produces movement of the shaft 38 along the screw shaft 54 and thus retraction of the tabs 16.

It is apparent that moving the tabs 16 into and out of the compartment 20 produces trimming of the boat 10 to maintain the boat at a proper attitude for maximum speed and minimum fuel consumption and to obtain increased visibility. The adjustability of the tabs 16 permits the boat to be trimmed at moderate speeds without the danger of overtrim at high speeds. The particular construction of the present invention in addition to providing adjustability of the trim tabs 16 through extension and retraction permits the tabs 16 to be completely withdrawn from the water so that maximum safety is achieved in a following sea. Further complete retraction avoids the danger of the tabs 16 becoming damaged if the boat is accidentally backed into another boat, piling or the like.

FIGS. 6 and 7 illustrate another preferred embodiment of the present invention in which the tabs 16 are mounted to extend through the bottom 14 of the boat 10 rather than through the transom 12. Again it is preferred that a pair of such tabs 16 be provided and these are similar in construction to those described above. Each of the tabs 16 is slidably mounted in a compartment 120 formed in the boat 10 and provided with a lateral opening 130 formed in the bottom 14 of the boat 10 at a point spaced forwardly of the transom 12. The compartment 120 is formed by an upper wall 122 extending upwardly from the rear edge edge of the opening 130 preferably at an angle of approximately 10 degrees, a lower wall 124 extending upwardly from the forward edge of the opening 130 in parallel relation with the upper wall 122, and side walls 126 and an inner wall 128 connecting edges of the walls 122 and 124. The opening 130 is sufficiently wide to permit the tabs 16 to be fully extended and the compartment 120 is of suflicient dimensions to permit the tabs 16 to be retracted to a position completely within the compartment 120.

The tabs 16 are preferably individually extendable and retractable from the compartments 120 and means similar to that described above are provided for producing movement of the tabs 16. The means comprise the shaft 38 fixed to the tabs 16 by the clamp and adapted to be moved along the screw shaft 54 by the motor 52 as described above.

The tabs 16 operate substantially similar and produce similar results and advantages as those described above iwith reference to the embodiments described above. However, because the tabs 16 extend from beneath the boat '10 and therefore tend to be urged upwardly against the bottom 14 of the boat 10 when they are extended a plurality of spaced wedge blocks are preferably affixed to the bottom 14 of the boat 10 to maintain the tabs 16 at the desired angle and to prevent the tabs from being bent or flexed upwardly against the boat 10.

In the embodiments described above suflicient space is left between the pair of tabs to permit the driving means such as the propellor shaft of a motor or the vertical shaft of the rudder assembly to extend therebetween. The particular tabs which have been so far described cannot extend a maximum distance when the boat is provided with a twin shaft rudder assembly positioned to extend through the hull of the boat. FIG. 8 illustrates a preferred modification of the tabs 16 for use on such installations. The tab 116 shown in FIG. 8 is similar in construction to the tabs 16 described above except the rear edge of the tab 116 is provided with a recessed portion for accommodating the vertical shafts (not shown) of a twin rudder assembly extending through the hull and to permit the tabs 116 to be extended past such shafts.

It is apparent that the particular trim means of the present invention can be readily provided with an indicating means for indicating the position of the tabs from within the boat. Such means could take the form of an indicator dial connected with the actuating shaft of the trim tabs by means operable to translate axial movement of these members to rotation of a pointer on the dial.

It is apparent that although I have described but several embodiments of the present invention many changes and modifications can be made therein without departing from the spirit of the invention as expressed by the appended claims.

I claim:

1. In a boat having a stern, means for trimming said boat comprising,

(a) a compartment being provided in said stern,

(b) said compartment having an elongated opening in the lower portion of said stern,

(c) a flat tab member carried in said compartment,

and

(d) means selectively operable to move said tab member from a retracted position in which said tab member is carried within said compartment longitudinally with respect to said boat to an extended position in which at least a portion of said tab member extends through said opening and exteriorly beyond the end of said boat to thereby increase the length of said boat.

2. The trimming means as defined in claim 1 and in which said boat is provided with a transom and said opening is provided in said transom.

3. The trimming means as defined in claim 1 and in which said boat is provided with a bottom and a transom and said opening is provided in said bottom adjacent said transom.

4. In a boat having a stern, means for trimming said boat comprising,

(a) a pair of spaced substantially planar flat compartments being formed in said stern one on each side of the longitudinal center line of said boat,

(h) each of said compartments being formed to extend downwardly toward said stern at a slight angle to the horizontal and being provided with a substantially horizontal opening at the stern end of said compartments,

(c) a pair of flat substantially rectangular tab members and means slidingly mounting one of said tab members in each of said compartments, and

(d) means selectively operable to individually move said tab member longitudinally with respect to said boat into and out of said compartments whereby said tab members are moved while maintaining a fixed angle with respect to said boat and when out of said compartments increase the effective length of said boat.

5. The trimming means as defined in claim 4 and in which said boat is provided with a transom and said openings are provided in the lower portion of said transom.

6. The trimming means as defined in claim 4 and in which said boat is provided with a bottom and a transom and said openings are provided in said bottom adjacent said transom.

7. In a boat having a stern, means for trimming said boat comprising,

(a) a compartment being provided in said stern,

(b) said compartment being provided in said stern,

(b) said compartment having an elongated opening in the lower portion of said stern,

(c) a flat tab member carried in said compartment,

said tab member in said compartment being disposed to extend downwardly toward said stern at an angle substantially ten degrees from the horizontal, and

(d) means selectively operable to move said tab member from a retracted position in which said tab member is carried within said compartment to an extended position in which at least a portion of said tab member extends through said opening and exteriorly of said boat.

8. A boat having a stern, means for trimming said boat comprising,

(a) a compartment being provided in said stern,

(b) said compartment having an elongated opening in the lower portion of said stern,

(c) a flat tab member carried in said compartment, said tab member in said compartment being disposed to extend downwardly towards said stern at an angle less than forty-five degrees from the horizontal, and

(d) means selectively operable to move said tab member from a retracted position in which said tab member is carried within said compartment to an extended position in which at least a portion of said tab member extends through said opening and exteriorly of said boat.

9. A boat having a stern, means for trimming said boat comprising,

(a) a pair of spaced substantially planar fiat compartments being formed in said stern one on each side of the longitudinal center line of said boat,

(b) each of said compartments being formed to extend downwardly toward said stern at an angle of substantially ten degrees from the horizontal and being provided with a substantially horizontal opening at the stern end of said compartments,

() a pair of flat substantially rectangular tab members and means slidably mounting one of said tab members in each of said compartments, and

(d) means selectively operable to individually move said tab members into and out of said compartments.

10. A boat having a stern, means for trimming said boat comprising,

(a) a pair of spaced substantially planar flat compartments being formed in said stern one on each side of a longitudinal center line of said boat,

(b) each of said compartments being formed to extend downwardly toward said stern at an angle less than forty-five degrees to the horizontal and being provided with a substantially horizontal opening at the stern end of said compartments,

(c) a pair of flat substantially rectangular tab members and means slidably mounting one of said tab 5 members in each of said compartments, and

(d) means selectively operable to individually move said tab members into and out of said compartments.

11. A boat having a stern, means for trimming said boat comprising,

(a) a pair of spaced substantially planar flat compartments being formed in said stern one on each side of the longitudinal center line of said boat,

(b) each of said compartments being formed to extend downwardly toward said stern at a slight angle to the horizontal and being provided with a substantially horizontal opening at the stern end of said compartments,

(0) a pair of fiat substantially rectangular tab members and means slidably mounting one of said tab members in each of said compartments.

((1) means selectively operable to individually move said tab members into and out of said compartments, and

(e) each of said tab members being provided with a medial recess portion on the trailing edge thereof adapted to permit the tab members to be moved past a vertical post or the like.

12. A boat having a stern, means for trimming said boat comprising,

(a) a pair of spaced substantially planar fiat compartments being formed in said stern one one each side of the longitudinal center line of said boat,

(b) each of said compartments being formed to extend downwardly toward said stern at a slight angle 35 to the horizontal and being provided with a substantially horizontal opening at the stem end of said compartment,

(c) a pair of flat substantially rectangular tab members and means slidably mounting one of said tab members in each of said compartments,

(d) means selectively operable to individually move said tab members into and out of said compartments, and

(e) each of said compartments comprising spaced parallel upper and lower walls joined by an inner end wall and vertically extending side walls, and said upper and lower walls extending in planes disposed downwardly toward said stem at angles of substantially ten degrees from the horizontal.

50 13. The trimming means as defined in claim 12 and in which said moving means comprises,

(a) a shaft extending through said end wall and secured to said tab member, and

(b) means carried within said boat for moving said shaft axially.

References Cited UNITED STATES PATENTS 1,475,460 11/1923 Thompson et al 114-l26 2,691,497 10/1954 Scheider et al. 114145 XR 3,046,928 7/1962 Sherrill ll466.5 3,159,131 12/1964 Frederick 114-66.5

MILTON BUCHLER, Primary Examiner. ANDREW H. FARRELL, Examiner. 

1. IN A BOAT HAVING A STERN, MEANS FOR TRIMMING SAID BOAT COMPRISING, (A) A COMPARTMENT BEING PROVIDED IN SAID STERN, (B) SAID COMPARTMENT HAVING AN ELONGATED OPENING IN THE LOWER PORTION OF SAID STERN, (C) A FLAT TAB MEMBER CARRIED IN SAID COMPARTMENT, AND (D) MEANS SELECTIVELY OPERABLE TO MOVE SAID TAB MEMBER FROM A RETRACTED POSITION IN WHICH SAID TAB MEMBER IS CARRIED WITHIN SAID COMPARTMENT LONGITUDINALLY WITH RESPECT TO SAID BOAT TO AN EXTENDED 